4 Department Circular 76, U. S. Dept. of Agriculture. 



be sufficiently strong to withstand the pressure applied to the press 

 and should be smooth faced on one side. 



The Bureau of Plant Industry has used with good success a drier 

 made by gluing two ordinary driers to the faces of a sheet of unf aced 

 corrugated strawboard. This does away with the necessity for the 

 use of both driers and strawboards, but is subject to the objection 

 that when plants with stout stems or rootstocks are pressed the 

 channels between the corrugations are likely to become jammed, thus 

 lessening the effectiveness of this drier as a ventilator. 



Collecting sheets. — Specimens are placed in the press in folders of 

 unglazed paper, in which they remain through the process of press- 

 ing and thereafter until mounted. The folders used by the Depart- 

 ment of Agriculture and by other institutions are blank sheets of 

 ordinary newspaper stock 16J by 23 inches, folded to ll^ by 16J 

 inches, but old newspapers cut to this size are quite as good. 



INSTRUCTIONS FOR COLLECTING. 



Herbaceous plants 3 feet high or less should be collected entire, 

 being bent in a V-shape or N -shape when necessary to accommodate 

 them to the collecting sheets (fig. 2). The root should be secured 

 entire, or, if very large, a portion sufficient to show its character 

 should be taken. Of shrubs or trees a branch about a foot long 

 should be collected, with specimens of the bark and of the sucker or 

 shoot leaves when these differ from those of the main branches. 

 Water plants and those of very fleshy texture require special treat- 

 ment, which is described in succeeding paragraphs. 



The specimens as collected should be placed in the collecting sheets 

 in the portfolio, the leaves being smoothed out and the other parts 

 disposed to best advantage. Roots should be washed thoroughly in 

 order to remove the mud. Many delicate flowers, such as those of 

 the dayflower and the evening primrose, have a tendency to collapse 

 even if perfectly fresh when placed in the press, but it is possible 

 to secure perfect specimens of these and similar flowers by applying 

 bits of paper, moistened with water, to the fresh flower and spread- 

 ing the petals out to their fullest extent when the plants are placed 

 in the portfolio. T\nien herbaceous plants are too large to collect 

 entire, they may be cut into sections of a size to fit the collecting 

 sheets. In the case of tall plants not only the upper part should 

 be collected but also a portion of the base, in order to show the 

 basal leaves, which are often very different from those of the upper 

 part of the stem. 



Several groups of plants require special attention. Sedges and 

 rushes are of little use unless collected in mature fruit. In all other 

 groups it should be the aim of the collector to secure specimens show- 



